Non-metallic vent cap

ABSTRACT

A vent assembly includes a base, an intake duct, an exhaust duct, and a cap assembly. The base includes a vertically oriented, outward facing primary surface and defines a duct aperture that extends through the outward facing primary surface. The base includes a metallic material. The intake duct is coupled to the base within the duct aperture, and the exhaust duct is oriented coaxially within the intake duct. An end of the exhaust duct extends distally beyond an end of the intake duct. The cap assembly includes first, second, and third members, wherein at least one of the first, second and third members includes a non-metallic material. The first member includes an intake aperture aligned with the duct aperture of the base and is sized to substantially cover the outward facing primary surface. The second member includes an exhaust aperture sized to receive the exhaust duct. The third member is positioned distally beyond an distal end of the exhaust duct in a flow path of exhaust gases exiting the exhaust duct.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to components of a vent systemfor heating appliances, and more particularly relates to vent capstructures suited for exhausting combustion products and intaking freshair for the heating appliance.

2. Related Art

Exterior intake and/or exhaust venting systems are generally known foruse in buildings and other such structures. Such vents can be used for avariety of venting purposes, for example, to vent fireplaces, furnaces,water heaters, boilers, dryers, exhaust fans, and a many other suchappliances and devices. Some such vents are primarily exhaust ventswhile others are primarily intake vents, and still others includestructure that allows them to function as both intake and exhaust vents.

In one example, chimneyless gas fireplaces often include intake/exhaustventing units that are mounted on the outside of an exterior wall thatprovide a through-the-wall connection to a double walled collinearducting of the gas fireplace. The double walled collinear ductingincludes an inner duct that serves as an outtake port for exhaust fumes,and an outer duct that serves as an intake port for ambient combustionair. The venting units generally include an inner and an outer duct.Further, the double walled ducting is connected to a series of basesthat have deflectors and heat shields. The venting unit has a series ofventing apertures with a vent cap attached thereto. The vent cap isutilized to cover both the air intake and the combustion productexhaust.

Regardless of the specific structure or use of the vent, most ventingsystems generally include a functional vent cap that covers the intakeand exhaust portions of the vent. However, many of the existing ventcaps are not aesthetically pleasing, may get hot due to high temperatureexhaust gases, and are exposed to the ambient atmosphere and thereforemay be damaged. An example venting unit that includes a functional ventcap and vent covers is shown and described in U.S. Pat. No. 6,484,712.

SUMMARY OF THE INVENTION

The present invention relates to vent assemblies that provide properfluid flow into and out of respective intake and exhaust apertures of avent, and minimize the flow of fluids exhausted from the exhaustaperture back into the intake aperture. The vent assembly comprises atleast one non-metallic member or at least one member that includesnon-metallic materials such as a compression molded ceramic fiber and abinder material.

One aspect of the invention relates to a vent assembly that includes abase, an intake duct, an exhaust duct, and a cap assembly. The baseincludes a vertically oriented, outward facing primary surface anddefines a duct aperture that extends through the outward facing primarysurface. The base includes a metallic material. The intake duct iscoupled to the base within the duct aperture, and the exhaust duct isoriented coaxially within the intake duct. An end of the exhaust ductextends distally beyond an end of the intake duct. The cap assemblyincludes first, second, and third members that each include anon-metallic material. The first member includes an intake aperturealigned with the duct aperture of the base and is sized to substantiallycover the outward facing primary surface. The second member includes anexhaust aperture sized to receive the exhaust duct. The third member ispositioned distally beyond an distal end of the exhaust duct in a flowpath of exhaust gases exiting the exhaust duct.

Another aspect of the invention relates to a vent assembly that includesa base member, an intake duct, an exhaust duct, and a vent cap assembly.The base member is configured for mounting to a wall structure. Theintake duct is coupled to the base member. The exhaust duct extendscoaxially through the intake duct and extends distally beyond an openend of the intake duct. The vent cap assembly is configured to mount tothe base member and the intake and exhaust ducts and includes aplurality of non-metallic structures configured to direct away from eachother fluids entering and exiting the intake and exhaust ducts.

A further aspect of the invention relates to a method of mounting aventing assembly to a vertically oriented surface. The method includesmounting a base plate to the vertically oriented surface, the base platedefining a vent aperture, mounting an intake duct to the base platewithin the vent aperture, and positioning an exhaust duct within theintake duct with an open end of the exhaust duct extending distallybeyond an open end of the intake duct. The method further includesdetachably mounting a vent cap assembly to the base plate wherein thevent cap assembly includes at least one cap member that comprise anon-metallic material. The vent cap assembly is configured to directintake air into the intake duct and direct exhaust gases out of theexhaust duct and away from the open end of the intake duct.

Another aspect of the invention relates to a method of manufacturing avent assembly, wherein the vent assembly includes a base member and avent cap assembly. The vent cap assembly includes at least first andsecond vent cap members. The method includes coupling the vent capmembers together with at least one first fastener that extends from thefirst vent cap member and into engagement with the second vent capmember, and coupling the vent cap assembly to the base member with atleast one second fastener that extends through the first vent cap memberinto engagement with the base member.

The above summary of the present invention is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. In particular, the example embodiments described below inrelation to the Figures are the application of the present invention toa heating appliance vent system, whereas other fields may be applicableto fulfill the purposes and intents of the present invention. Figures inthe detailed description that follow more particularly exemplify certainembodiments of the invention. While certain embodiments will beillustrated and describe embodiments of the invention, the invention isnot limited to use in such embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of one example vent assembly according toprincipals of the present invention;

FIG. 2 is an exploded perspective view of the vent assembly as shown inFIG. 1;

FIG. 3 is a side view of the vent assembly shown in FIG. 1;

FIG. 4 is a front view of the vent assembly shown in FIG. 1;

FIG. 5 is a cross sectional view taken along cross section indicators5-5 in FIG. 4;

FIG. 6 is a cross sectional view taken along cross section indicators6-6 shown in FIG. 4;

FIG. 7 is an exploded perspective view of a base assembly portion of thevent assembly shown in FIG. 1;

FIG. 8 is a rear view of a first cap member of the vent assembly shownin FIG. 1;

FIG. 9 is a rear view of a second cap member of the vent assembly shownin FIG. 1; and

FIG. 10 is a rear view of a third cap member of the vent assembly shownin FIG. 1.

While the invention is amenable to various modifications and alternateforms, specifics thereof have been shown by way of example and thedrawings, and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally relates to vent systems, vent assembliesand related methods of venting and assembling vent systems and ventassembly components. One aspect of the invention relates to the use ofnon-metallic materials with a vent assembly, in particular, portions ofa vent cap or vent cover of a vent assembly that are exposed forviewing.

The vent systems and assemblies are typically associated with heatingappliances that require at least one of a source of inlet air and anexhaust outlet. The example systems and methods described herein includean exhaust member configured to exhaust combustion products away fromthe heating appliance through an exhaust portion of the vent assembly,and an intake member configured to provide a source of intake air to theheating appliance. The exhaust and intake members are preferablycoaxially oriented with the exhaust member extending within the intakemember. This coaxial arrangement (sometimes referred to as a B-ventarrangement) provides cooling of exhaust gases in the exhaust member viaheat transfer with the intake air flowing through the intake member.Other embodiments can provide different arrangements of the exhaust andintake members relative to each other, or provide exhaust or intakefunctions rather than both functions.

The use of metallic materials for components of a vent assembly iscommon. Metallic materials can have certain drawbacks related to, forexample, safety issues (e.g., related to exposed heated surfaces of thevent assembly), aesthetics and appearance, and replaceability ofcomponents. The use of non-metallic materials for at least some of thecomponents of a vent assembly address some or all of the drawbacks ofmetallic vent assemblies. For example, some non-metallic materials suchas the compression molded ceramic materials disclosed in U.S. PublishedPatent Application No. 2003/0049575, which patent application isincorporated herein by reference in its entirety, possess heatdissipating properties that result in improved safety.

Some non-metallic materials can be molded, caste, or otherwise formed orshaped to include details and features than improve aesthetics andappearance of a resulting product. The moldability of some types ofnon-metallic materials provide for flexibility in generating complexcomponent shapes and structures that could be more difficult and costlyto produce if using metallic materials. Some types of non-metallicmaterials are useful for providing desired surface finishes such astexture, color and grain that match the appearance of exposed structuresthat surround the vent assembly. For example, a vent cap or vent covermade in part from a non-material material such as the compression moldedceramic material mentioned above can be formed with a stucco styleexposed surface that matches a stucco surface of the wall structure towhich the vent cap/cover is mounted.

Referring now to FIGS. 1-10, an example vent assembly 10 includes a base12, an intake duct 14, an exhaust duct 16, and a vent cap assembly 18.The vent cap assembly 18 includes first, second and third cap members20, 22, 24, first and second screens 26, 28, and an exhaust duct base30. Preferably, at least one of the cap members 20, 22, 24 comprises anon-metallic material such as the compression molded ceramic materialdisclosed in U.S. Patent Application No. 2003/0049575. While the ventcap assembly 18 includes three separate cap members, other embodimentsmay have a similar resulting configuration by integrally forming two ormore of the cap members 20, 22, 24 as a single piece.

Referring to FIG. 2, the base 12 includes a vent aperture 40, a waterflashing 42, and an exposed outward facing surface 43. The base 12 maybe coupled as a sub-assembly 13 with the intake duct 14 and heat shield32 (see FIG. 7). The sub-assembly 13 is preferably mounted to an outsidesurface of a wall structure such as an exterior wall of a livingstructure (e.g., residential home or commercial building). The wallstructure typically includes a hole having a diameter equal to thediameter of the heat shield 32. When the base 12 is mounted against thewall structure, the intake duct 14 is positioned within the wallstructure such that an inner open end 44 of the intake duct is in aposition for attachment to further ducting extending within the livingstructure. Typically, the further ducting (not shown) is coupled to aheating appliance that requires intake of air drawn in through theintake duct 14.

When mounting the base 12 to the wall structure, the base 12 may bepermanently or semi-permanently mounted with fasteners, adhesives, orthe like, thereby providing a mounting surface for the vent cap assembly18.

A outer open end 44 of the intake duct 44 terminates at a point distallybeyond the outward facing surface 43 of the base 12. The intake duct 14may also include a flange 46 or other structure to help mount the intakeduct 14 to the base 12 within the vent aperture 40.

The exhaust duct 16 is coaxially mounted within the intake duct 14 asshown in FIGS. 3, 5 and 6. An inward open end 52 of the exhaust duct 16extends axially beyond the inward open end 45 of the intake duct 14 toprovide, for example, easier connection to further exhaust ducting thatextends within the living structure. An outward open end 50 of theexhaust duct 16 extends distally beyond the outer open end 44 of theintake duct 14 so as to be positioned within the vent cap assembly 18when the vent cap assembly is mounted to the base (see FIGS. 5 and 6).The exhaust duct 16 may also include a flange member 54 at the outeropen end 50 that can be used to help attach the exhaust duct 16 withinthe vent cap assembly 18. The first cap member 20 includes an outwardfacing surface 60, an intake vent aperture 62, a water shield 64 formedacross the top of the intake vent aperture 62, and first and second setsof fastener apertures 66, 68. The first cap member 20 is sized tosubstantially cover the outward facing surface 43 of the base 12 (seeFIG. 4).

In other embodiments, the first cap member 20 may be sized to overlapand completely conceal and/or cover all of the base 12 from view, inparticular from a front view as shown in FIG. 4. In other embodiments,the first cap member 20 may have a smaller size such that portions ofthe base 12 are exposed. In such an embodiment, the exposed portions ofbase 12 can be covered by the exterior cover of the building structuresuch as siding, stucco, or the like to provide a more permanent mountingof the base 12 to the wall structure.

The water shield 64 extends outwardly away from the outward facingsurface a distance approximately equal to a width of the inflow openingdefined by the second cap member 22 (described in further detail below).The water shield 64 helps to prevent water from flowing into an interiordefined by the vent cap assembly 18 the water shield 64 defines agenerally curved structure such that any precipitation fallingvertically onto a top surface of the water shield 64 is directedlaterally to one of the sides of the venting assembly 10 and away fromentering into the intake vent 14 via the vent opening 62.

The second set of fastener apertures 68 are sized to receive the secondset of fasteners 36, which are used to positively attach the first capmember 20 to the base 12. When the vent cap assembly 18 is assembledtogether, securing the first cap member to the base 12 results inpositive attachment of the entire vent cap assembly 18 to the base 12and thereby attachment to the wall structure to which the base 12 isalso mounted.

The second cap member 22 includes an outward facing surface 70, anexhaust vent aperture 72, a plurality of connecting members 74 thatdefine a plurality of inflow openings 76, and fastener apertures 78. Theexhaust vent aperture 72 is sized to receive the exhaust duct 16 withthe open end 50 of the exhaust duct being positioned flush mounted withthe outward facing surface 70 or extending distally beyond the outwardfacing surface 70 as shown in FIGS. 5 and 6. The exhaust duct 16 ismounted with a positive connection to the second cap member by couplingthe exhaust duct base 30 against the flange 54 of the exhaust duct andthen securing the exhaust duct base 30 to the outward facing surface 70of the second cap member 22 with, for example, fasteners or adhesives.

The connecting members 74 act as, for example, dividers, standoffmembers or separators that space apart the second cap member 22 from thefirst cap member 20. A spacing between the first and second cap members20, 22 is preferred in order for air to flow into the intake duct 14 viathe intake aperture 62 of the first vent cap member when the vent capassembly 18 is assembled together. The connecting member 74, while shownin this embodiment integrally formed with the structure of the secondcap member 22 that defines the outward facing surface 70, otherembodiments may include a connecting member that is separate anddistinct. In other examples, the connecting members may be integrallyformed with the first cap member 20. Furthermore, while four connectingmembers 74 are shown in the present embodiment, other embodiments mayinclude fewer or more than four connecting members while providingseparation of the first and second cap members 20, 22.

The fastener apertures 78 extend through the connecting members 74 suchthat the first set of fasteners 34 can pass through the apertures 78.The apertures 78 align with the first set of fastener apertures 66 inthe first cap member 20 so that the fasteners 34 can pass through theapertures 68, through the apertures 78, and be connected to the thirdcap member 24 (discussed in further detail below) for assembly of thefirst, second and third cap members 20, 22, 24 as a subassembly of theventing assembly 10.

The third cap member 24 includes an outward facing surface 80, aplurality of connecting members 82, a plurality of outflow openings 84defined between the connecting members 82, and a plurality of fastenerreceivers 86 defined within the connecting members 82 (see FIG. 9). Theconnecting members 82 provide spacing and separation between the secondand third cap members 22, 24. Separation between the second and thirdcap members 22, 24 or at least some openings or apertures should bedefined within the second or third cap members 22, 24 to provide a flowpath for exhaust gases leaving the exhaust duct 16 via the outward openend 50. In this embodiment, the connecting members 82 define theplurality of outward flow openings 84 around a circumference of thethird cap member 24 to provide such a flow path. In other embodiments,the connecting members 82 extend from the outward facing surface 70 ofthe second cap member rather than from the third cap member 24 as shownin the Figures. In still further embodiments, the connecting members 82may be separate and distinct members that are coupled between the secondand third cap members. In still further embodiments, the second andthird cap members are integrally formed as a single piece rather thanthe two separate pieces illustrated in the figures.

The fastener receivers 86 defined in the connecting members 82 areexposed in a rearward direction so as to receive the fasteners 34 thathave been extended through the first and second cap members. In otherembodiments, fasteners may be, for example, co-molded into the first,second, or third cap members 20, 22, 24 to provide the desired couplingfunction of the various cap members.

An advantage of providing separate cap members in the vent cap assembly18 is to enable positioning of the first and second screens 26, 28 inthe space defined between the first and second cap members and betweenthe second and third cap members, respectively. In other embodiments,the screens 26, 28 may be co-molded or otherwise formed within one ormore of the cap members. In still further embodiments, wherein two ormore of the cap members are integrally formed as a single piece, thescreens may be properly positioned during the process of molding thosecap members as a single piece. The screens 26, 28 preferably overlap theopenings 76, 84 defined in the second and third cap members 22, 24 toprevent objects (e.g., animals and insects) from entering the intake andexhaust vents.

In one embodiment, the first, second and third cap members 20, 22, 24each comprise substantially a non-metallic material such as thecompression molded ceramic material described above. In someembodiments, the cap members 20, 22, 24 may include a combination ofdifferent non-metallic materials. In other embodiments, metallicfeatures may be co-molded or otherwise integrated into one or more ofthe cap members.

One advantage of the vent cap assembly 18 is that it substantiallyconceals all metallic features of the venting assembly 10. In fact, theonly metal features that are viewable in the front view of FIG. 4 is thewater flashing 42, a top portion of the base 12 (which would typicallybe covered by a decorative surface member—e.g., siding, brick, stucco,etc.), and heads of the fasteners 36. Even in the side view of FIG. 3,the only additional metal objects that are viewable are portions of thescreens 26, 28. Thus, the vent cap assembly 18 can provide a moreaesthetically pleasing design that blends into the décor of itssurroundings (e.g., decorative design or appearance of the wallstructure to which the vent assembly 10 is mounted).

Another benefit of using non-metallic material for some or all of thevent cap assembly components is the added safety some non-metallicmaterials provide. For example, the compression molded ceramic materialdescribed above can maintain a relatively safe surface temperature evenafter extended periods of heated gases being applied to a non-exposed,opposite surface of the cap assembly.

While the present embodiment includes a separate base member to whichthe intake duct and heat shield are mounted, other embodiments may bepossible that do not include such a base member. For example, the intakeduct 14 and heat shield 32 may be connected directly to the first capmember of the vent cap assembly 18 and the first cap member 20 iscoupled directly to the wall structure for mounting of the ventingassembly to a horizontal vent. In other embodiments, the base may beintegrally formed into one of the cap members. In still furtherembodiments, one or more of the cap members 20, 22, 24 may be replacedwith a metallic member. For example, the first cap member 20 may becompletely eliminated or replaced by a water shield that is coupled tothe base 12, whereas the second and third cap members 22, 24 areconnected directly to the base 12. All of these and other embodiments,configurations, and arrangements may be possible.

One advantage of the embodiment disclosed with reference to FIGS. 1-10is the ability to easily replace the vent cap assembly portion 18 forany desired reason. Because the base 12 is mounted to a wall structurewith a more permanent mounting configuration, the vent cap assembly 18can be replaced for any number of reasons. For example, a new vent capassembly can provide a new look and feel for the vent assembly (e.g., adesign or pattern being added to the exposed outward facing surface 80of the third cap member), or be used to replace broken or damagedcomponents of the vent cap assembly 18.

Another aspect of the disclosed embodiments relates to a method ofassembling portions of the venting assembly so as to conceal metalobjects such as fasteners that are used to assemble components of theventing assembly. In one example, the vent cap assembly 18 is coupledtogether using fasteners that extend from a back side of the first capmember wherein they are concealed from view, through the second capmember 22 and into engagement with the third cap member 24. In this way,a single set of fasteners can be used to couple all of the cap memberstogether. A fasteners may also be used to concurrently capture thescreens in proper position covering the inflow and outflow openings 76,84.

The present invention should not be considered limited to the particularexamples or materials described above, but rather should be understoodto cover all aspects of the invention as fairly set out in the attachedclaims. Various modifications, equivalent processes, as well as numerousstructures to which the present invention may be applicable will bereadily apparent to those of skill in the art to which the presentinvention is directed upon review of the instant specification.

1. A vent assembly, comprising: a base including a vertically oriented,outward facing primary surface and defining a duct aperture that extendsthrough the outward facing primary surface, the base comprising ametallic material; an intake duct coupled to the base within the ductaperture, and an exhaust duct oriented coaxially within the intake duct,wherein an end of the exhaust duct extending distally beyond an end ofthe intake duct; and a cap assembly comprising first, second, and thirdmembers that each comprise a non-metallic material, the first memberhaving an intake aperture aligned with the duct aperture of the base andsized to substantially cover the outward facing primary surface, thesecond member having an exhaust aperture sized to receive the exhaustduct, and the third member positioned distally beyond an distal end ofthe exhaust duct in a flow path of exhaust gases exiting the exhaustduct.
 2. The vent assembly of claim 1, wherein the first, second andthird cap assembly members are spaced apart from each in a directionalong an axis of the exhaust duct.
 3. The vent assembly of claim 1,wherein the cap assembly is configured for assembly together as a singleunit that is coupled to and removable from the base as a single unit. 4.The vent assembly of claim 1, wherein the non-metallic materialcomprises a ceramic fiber and a binder.
 5. The vent assembly of claim 1,wherein the first cap member includes a lip positioned vertically abovethe intake aperture that protrudes in a direction along a length of theexhaust duct.
 6. The vent assembly of claim 1, wherein the second andthird cap members each include a primary surface facing away from thebase and a plurality of engagement member extending towards the base. 7.A vent assembly, comprising: a base member configured for mounting to awall structure; a intake duct coupled to the base member; an exhaustduct extending coaxially through the intake duct and extending distallybeyond an open end of the intake duct; and a vent cap assemblyconfigured to mount to the base member and the intake and exhaust ducts,the vent cap assembly comprising at least one non-metallic structureconfigured to direct away from each other fluids entering and exitingthe intake and exhaust ducts.
 8. The vent assembly of claim 7, whereinthe vent cap assembly comprises a first non-metallic member that definesan aperture sized to receive the intake duct.
 9. The vent assembly ofclaim 8, wherein the vent cap assembly further comprises a secondnon-metallic member that defines an aperture sized to receive theexhaust duct, wherein the intake duct terminates between the firstnon-metallic member and the second non-metallic member.
 10. The ventassembly of claim 9, wherein the vent cap assembly further comprises athird non-metallic member that is oriented at least partially in a flowpath of exhaust exiting the exhaust duct, wherein the exhaust ductterminates between the second non-metallic member and the thirdnon-metallic member.
 11. The vent assembly of claim 7, wherein thenon-metallic members comprise a ceramic fiber and a binder.
 12. The ventassembly of claim 7, wherein the non-metallic members comprise acompression molded ceramic fiber.
 13. The vent assembly of claim 7,wherein the vent cap assembly is configured to substantially conceal thebase member from view.
 14. A method of mounting a venting assembly to avertically oriented surface, the method comprising: mounting a baseplate to the vertically oriented surface, the base plate defining a ventaperture; mounting an intake duct to the base plate within the ventaperture; positioning an exhaust duct within the intake duct with anopen end of the exhaust duct extending distally beyond an open end ofthe intake duct; and detachably mounting a vent cap assembly to the baseplate, the vent cap assembly including at least one cap member thatcomprise a non-metallic material, the vent cap assembly configured todirect intake air into the intake duct and direct exhaust gases out ofthe exhaust duct and away from the open end of the intake duct.
 15. Themethod of claim 14, wherein the vent cap assembly includes a pluralityof cap members that each comprise a non-metallic material, the methodfurther comprising coupling the plurality of cap members to each otherbefore mounting the vent cap assembly to the base plate.
 16. The methodof claim 14, wherein the at least one cap member comprises a compressionmolded ceramic material.
 17. The method of claim 14, wherein the ventcap assembly includes a plurality of cap members, and one of the capmembers is mounted to a distal end of the exhaust duct to provide abarrier between the open end of the exhaust duct and the open end of theintake duct.
 18. The method of claim 14, further comprisingsubstantially concealing the base member from view when mounting thevent cap assembly to the base member.
 19. A method of manufacturing avent assembly, the vent assembly including a base member and a vent capassembly, the vent cap assembly including at least first and second ventcap members, the method comprising the steps of: coupling the vent capmembers together with at least one first fastener that extends from thefirst vent cap member and into engagement with the second vent capmember; and coupling the vent cap assembly to the base member with atleast one second fastener that extends through the first vent cap memberinto engagement with the base member.
 20. The method of claim 19,further comprising forming at least one of the vent cap members from anon-metallic material.
 21. The method of claim 19, further comprisingforming at least one of the vent cap members from a compression moldedceramic material.
 22. The method of claim 19, wherein the at least onefirst fastener is concealed from view when the vent cap assembly iscoupled to the base member.
 23. The method of claim 19, furthercomprising mounting an intake duct to the base member in alignment witha vent aperture defined in the base member.
 24. The method of claim 23,further comprising aligning an exhaust member co-axially within theintake member, the exhaust member extending distally beyond an open endof the intake member.
 25. The method of claim 24, further comprisingmounting the second vent cap member adjacent to the open end of theexhaust member at a position between the open ends of the intake andexhaust ducts.
 26. The method of claim 19, wherein the vent cap assemblyfurther includes a third cap member, and coupling the vent cap memberstogether includes extending the at least one fastener through the secondvent cap member and into engagement with the third vent cap member.